The passing of Justice Antonin Scalia has made the issue of would-be Supreme Court appointees a central topic in the 2016 Presidential race. And no GOP hopeful has been quicker to capitalize on the issue than Texas Senator Ted Cruz, who clerked for Chief Justice William Rehnquist and has made his vow to appoint unwavering conservative judges a distinguishing factor, and frequently occurring applause line, in his campaign stump speeches.

Cruz has been highly critical of Chief Justice John Roberts for "liberal" Supreme Court decisions upholding the Affordable Care Act and marriage equality, though he supported his nomination to the Supreme Court while working as an associate deputy attorney general in the last Bush administration. Cruz has said that if he were President he would have instead appointed his former boss Mike Luttig to the bench, who he claims would have been far more conservative.

So just who is this conservative stalwart that a President Cruz would have sitting on the nation's highest court? We dug in to our database and found surprising information casting doubts about where Luttig stands on issues such as Obamacare and gay marriage. Namely that he was a major donor to the Democratic Congressional Campaign Committee and helped reelect Nancy Pelosi as Speaker of the House with a $1,000 dollar campaign contribution in 2008.

In fairness to Luttig, he's also donated money to Republican politicians such as Senator Tim Scott and two other former US Senators from Virginia. And it's certainly not unusual for DC insiders to give evenhandedly to politicians on both sides of the aisle. But Cruz has frequently criticized such behavior and made Trump's contributions to Democrats (especially his support of Nancy Pelosi) a major line of attack in his campaign against the Washington establishment. See below:

So how do the campaign contributions of Cruz's would-be Chief Justice compare with John Roberts? Prior to his appointment, Roberts had donated only to Republican candidates, primarily in his home state of Indiana. His Crowdpac score, which is calculated by his pattern of political giving, is a conservative 6.5C - over four points to the right of Luttig, a relative moderate 2.2C.

Now of course campaign contributions only tell part of the story. Luttig's history of decisions as a judge should also be taken into consideration when speculating how he might act on the Supreme Court. But if you believe, as we do and as Ted Cruz does, that political contributions say a lot about where you stand on the issues, Luttig's support for the party that passed the Affordable Care Act shouldn't be ignored.